Many properties of polymer nanocomposites are determined by the anisoptropy and orientation of the sequestered nanomaterials. In some cases, the anisotropy of the nanomaterial is useful only for the realization of an isotropic system property. For example, the bulk mechanical properties of polymer melts may be enhanced by the inclusion of high-aspect ratio nanoparticles, which have a lower percolation threshold than an equivalent mass of spherical nanoparticles (Pike et al., 1974, Physical Review B 10:1421-1434). In other cases, the anisotropy of the sequestered nanomaterial imparts “higher level” anisotropy in the bulk properties of the system. Controlled orientation of nanomaterial inclusions in polymer films produced demonstrations of anisotropic permeability (Pike et al., 1974, Physical Review B 10:1421-1434; Holt et al., 2006, Science 2006, 312:1034-1037) thermal (Choi, et al., 2003, J. Appl. Phys. 94:6034-6039; Moniruzzaman et al., 2006, Macromolecules 39:5194-5205) and electrical (Du, et al. 2005, Physical Review B 72:121404-4; Sandler et al., 2003, Polymer 44:5893-5899) conductivity, enhanced mechanical properties (Haggenmueller et al., 2000, Chemical Physics Letters 330:219-225; Thostenson and Chou, 2002, J. Phys. D-Appl. Phys. 35:L77-L80), and photovoltaic activity (Ahir et al., 2008, Polymer 49:3841-3854; Kang et al., 2006, Solar Energy Materials and Cells 90:166-174).
Current methods for controlling orientation in nanocomposite materials, however, are limited by their effectiveness and scalability. For example, for polymeric materials containing single-walled carbon nanotubes (SWNTs), mechanical shear (Jin et al., 1998, Appl. Phys. Lett. 73:1197-1199), anisotropic flow (Haggenmueller et al., 2000, Chemical Physics Letters 330:219-225; Kim et al., 2007, Nano Lett. 7:2806-2811), gel extrusion (Vigolo et al., 2000, Science 290:1331-1334), melt stretching (Fagan et al., 2007 Phys. Rev. Lett. 98:147402), magnetic fields (Lagerwall et al., 2007, Advanced Materials 19:359-364; Walters et al., 2001, Chemical Physics Letters 338:14-20), and electric fields (Park et al., 2006, Journal of Polymer Science Part B: Polymer Physics 44:1751-1762) have been used to varying effect to induce nanotube alignment. Despite these efforts, the fabrication of aligned SWNT-polymer nanocomposite matrices remains difficult, particularly in thin-film geometries where vertical alignment of the SWNTs in polymer films is attractive for applications in size and chemo-selective transport (Majumder et al., 2005, J Am Chem Soc. 127:9062-9070; Lopez-Lorente et al., 2010, Anal Chem. 82(13):5399-407). Thus, a need exists for systems and methods of aligning nanomaterials within mesophases and polymerized nanocomposites. The present invention fulfills these needs.